JP2023504739A - Method and system for maintaining lateral control of an unmanned aerial vehicle during landing - Google Patents

Abstract

Systems, apparatus and methods include an unmanned aerial vehicle (UAV) (101), one or more inner wing panels (107) of the UAV, one or more outer wing panels (109) of the UAV, and one or more inner at least one inboard propeller (140) mounted on at least one engine (110) located in a wing panel and at least one engine (110) located in one or more outer wing panels; including at least one tip propeller (141) and at least one microcontroller (420), wherein the microcontroller determines the angular position of the at least one inboard propeller and the propeller that the at least one inboard propeller grounds upon landing. It is configured to send a signal to stop rotation of the at least one inboard propeller so that it is held in an attitude that provides blade clearance. [Selection drawing] Fig. 3A

Description

TECHNICAL FIELD The present embodiments relate generally to unmanned aerial vehicles (UAVs), and more particularly to maintaining lateral control of a UAV during landing with inboard propellers horizontal.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/945,815, filed December 9, 2019, the contents of which are for all purposes incorporated herein by reference.

Unmanned Aerial Vehicles (UAVs), such as high endurance aircraft, are light aircraft capable of controlled sustained flight. A UAV may be associated with a ground operator for two-way communication.

An embodiment may include a system for maintaining lateral control of an unmanned aerial vehicle (UAV) during takeoff and landing with the inboard propeller horizontal. In one embodiment, the UAV is a high altitude long endurance solar powered aircraft.

An embodiment of the system includes an unmanned aerial vehicle (UAV), one or more inner wing panels of the UAV, and one or more outer wing panels of the UAV, wherein the one or more outer wing panels comprise one or more one or more outer wing panels positioned on either side of the inner wing panel, the one or more outer wing panels being oriented at an upward angle to a plane formed by the one or more inner wing panels; , at least one inboard propeller mounted on at least one engine located on one or more inboard wing panels, and at least one inboard propeller mounted on at least one engine located on one or more outboard wing panels. at least one microcontroller in communication with the tip propeller and at least one engine located on one or more inner wing panels for determining the angular position of the at least one inboard propeller, the at least one inboard propeller being and at least one microcontroller configured to send a signal to stop rotation of the at least one inboard propeller so that the propeller blades are held in an attitude that provides ground clearance during landing.

In additional system embodiments, the UAV may be a high endurance aircraft. In additional system embodiments, a solar array may cover at least a portion of one or more inner wing panels and one or more outer wing panels. Additional system embodiments may further include one or more landing pods of the UAV, which are attached to one or more inner wing panels of the UAV to assist in landing the UAV. be able to. In additional system embodiments, the distance (d ₁ ) from the center of the propeller hub to the tip of the at least one inboard propeller is greater than the height of the one or more landing pods, and the at least one inboard propeller is: When the UAV is on the ground, it can hit the ground during rotation of at least one inboard propeller. In additional system embodiments, the at least one outboard propeller may be identical to the at least one inboard propeller, and the at least one outboard propeller is free to rotate when the UAV is on the ground. can be done.

Additional system embodiments may further include a position sensor in communication with the microcontroller, the position sensor detecting the position of the at least one inboard propeller. In additional system embodiments, the position sensor may be a Hall effect rotary position sensor. In additional system embodiments, the at least one microcontroller further determines the altitude of the UAV and sends a signal to stop rotation of the at least one inboard propeller when the determined altitude is below a threshold altitude. can be configured to In additional system embodiments, the at least one microcontroller further controls rotation of the at least one outboard propeller while the at least one inboard propeller is held in an orientation that provides ground clearance for the propeller blades. It may be configured to transmit a coordinating signal. In additional system embodiments, the at least one microcontroller further determines an altitude of the UAV and transmits a signal to initiate rotation of the at least one inboard propeller when the determined altitude is above a threshold altitude. can be configured to

A method embodiment includes the steps of determining, by at least one microcontroller, an altitude of an unmanned aerial vehicle (UAV); and by at least one microcontroller communicating with at least one engine of the UAV, connected to the at least one engine. identifying the angular position of at least one inboard propeller, wherein the at least one inboard propeller is located on one or more inner wing panels; and if the identified altitude is below a threshold altitude, sending by the at least one microcontroller a signal to stop rotation of the at least one inboard propeller such that the at least one inboard propeller is held in an orientation that provides ground clearance for the propeller blades. and the at least one inboard propeller may hit the ground during rotation of the at least one inboard propeller when the UAV is on the ground.

Additional method embodiments include at least one inboard propeller connected to at least one engine by at least one microcontroller while at least one inboard propeller is held in an orientation that provides clearance between the propeller blades and the ground during landing. The step of transmitting a signal to coordinate rotation of one outboard propeller may be further included, wherein the at least one outboard propeller is positioned on one or more outer wing panels. In additional method embodiments, the at least one outboard propeller is identical to the at least one inboard propeller, and the at least one outboard propeller is free to rotate when the UAV is on the ground.

Another system embodiment is an unmanned aerial vehicle (UAV) and at least one inboard propeller attached to at least one engine of the UAV, wherein the at least one inboard propeller is driven when the UAV is on the ground. at least one inboard propeller, wherein at least a portion of the at least one inboard propeller may contact the ground during rotation of the propeller, and at least one tip propeller attached to at least one engine of the UAV, the UAV at least one tip propeller that is free to rotate without contacting the surface during rotation of said at least one tip propeller when located on the surface of the earth; A controller determines the angular position of the at least one inboard propeller and signals the at least one inboard propeller such that the at least one inboard propeller is held in an orientation that provides clearance between the propeller blades and the ground surface. and at least one microcontroller configured to transmit.

In additional system embodiments, the at least one microcontroller further for guiding the UAV for landing while the at least one inboard propeller is held in an attitude that provides ground clearance for the propeller blades. to the at least one tip propeller, the at least one tip propeller maintaining lateral control of the UAV during landing. In additional system embodiments, the at least one microcontroller further provides thrust to guide the UAV for takeoff while the at least one inboard propeller is in an attitude that provides ground clearance for the propeller blades. The at least one microcontroller is configured to send a coordinating signal to at least one tip propeller, the at least one tip propeller maintaining lateral control of the UAV during takeoff; It is configured to send a signal to the at least one inboard propeller after takeoff so that the propellers begin to rotate.

Additional system embodiments may further include one or more landing pods to assist in the safe landing of the UAV on the ground, the distance (d ₁ ) is greater _than the height (d2) of the _one or more landing pods and the distance (d1) from the center of the propeller hub to the tip of at least one leading propeller is the propeller hub of at least one leading propeller greater than or equal to the height ( _d3 ) from the center of the to the bottom edge of the landing pod(s). Additional system embodiments are one or more inner wing panels of a UAV, where at least one inboard propeller is mounted, and one or more outer wing panels of the UAV. at least one tip propeller attached to one or more outer wing panels, one or more outer wing panels being positioned on either side of one or more inner wing panels, one or more outer wing panels comprising: and one or more outer wing panels disposed at an upward angle to a plane formed by the one or more inner wing panels. Additional system embodiments may further include a position sensor in communication with the microcontroller, the position sensor detecting the position of the at least one inboard propeller.

The components in the figures are not necessarily to scale, emphasis instead being placed on explaining the principles of the invention. Like numbers refer to corresponding parts throughout the various drawings. Embodiments are illustrated by way of illustration and not limitation in the form of the accompanying drawings.
FIG. 1 illustrates a system for maintaining lateral control of an unmanned aerial vehicle during landing with the inboard propellers leveled, according to one embodiment. 2 shows a top perspective view of the unmanned aerial vehicle of FIG. 1. FIG. FIG. 3A shows a schematic diagram of the wing panel and associated propeller of the unmanned aerial vehicle of FIG. FIG. 3B shows a schematic diagram of a wing panel and a two-bladed propeller held against the wing panel. FIG. 3C shows a schematic diagram of a wing panel and a three-blade propeller held against the wing panel. FIG. 4 illustrates an exemplary top-level functional block diagram of an embodiment of a computing device. FIG. 5 shows a flowchart of the steps performed by the microcontroller for UAV landing. FIG. 6 shows a flowchart of the steps performed by the microcontroller for UAV takeoff.

Referring to FIG. 1, there is shown a system 100 for maintaining lateral control of an unmanned aerial vehicle (UAV) 101 during landing with the inboard propellers leveled. UAVs are pilotless aircraft on board and can fly autonomously or remotely. Large UAVs may use landing pods for safe landing, which can create extra weight and drag. UAVs can use differential thrust from the UAV's propulsion system for lateral control in several flight states, including takeoff and landing. In one embodiment, UAV 101 is a high endurance aircraft. In one embodiment, UAV 101 may have 3 or more motors, eg, 3 to 40 motors, and a wingspan of 100 feet to 400 feet. In one embodiment, the UAV 101 may have a wingspan of approximately 260 feet and may be propelled by multiple motors, e.g., ten electric motors driven by a solar array covering the surface of the wing, Zero emissions can thereby be achieved. The UAV 101 is designed to fly above the clouds at an altitude of approximately 65,000 feet above sea level and conduct continuous long-range missions for up to several months without landing.

The UAV 101 works best at high altitudes and is capable of sustained flight for significant periods of time without resorting to landing. In one embodiment, UAV 101 may have a weight of approximately 3,000 pounds.

UAV 101 further includes at least one motor 110 coupled to UAV 101 for propulsion of UAV 101 . In one embodiment, motor 110 is a brushless DC motor of conventional configuration including an in-runner rotor electrically connected with a W-configuration of windings around a modified armature. Motor 110 may have a casing made of steel or other high strength material to enclose and protect the motor. A stator is disposed around the outer circumference of the rotor and the stator has a back iron for containing the magnetic field of the stator. The rotor can be formed of any suitable magnet, including permanent magnets such as neodymium and praseodymium, and electromagnets. The stator may have an armature constructed from laminated layers of electrical steel, such as silicon steel, with an oxide film between each steel layer to reduce induced ring currents and increase efficiency of the motor 110 . are placed. Other armature materials may include iron or amorphous steel.

In one embodiment, motor 110 is configured to have windings wrapped around iron teeth. Additionally, there may be a layer of magnets on the outside of the motor 110 that remains attached to the motor 110 until the temperature drops to about -80°C. This is advantageous because UAVs 108 often fly at night and at high altitudes in temperatures approaching -80°C.

Some motors in the art may be iron free to avoid hysteresis and eddy current losses where energy is wasted in the form of heat. In one embodiment, the motor 110 may incorporate Permendur (a soft magnetic cobalt-iron alloy with equal amounts of iron and cobalt) such as Hiperco®. Permendur has very low hysteresis and eddy current losses and often outperforms iron-free motors. In addition, the iron (1) provides mechanical support for the windings, (2) provides inductance, thus eliminating the need for an external inductor, (3) provides a means of conducting heat away from the motor, and (4) ) provides a very thin air gap, so much less magnetic material is needed to create the magnetic field; It has very important properties not found in iron-free motors, such as the ability to avoid magnetic fields from such copper.

As shown in FIG. 2, UAV 101 includes one or more inner wing panels 107 and one or more outer wing panels 109, a central panel 108, and a plurality of inboard propellers 140 associated with each inner wing panel 107. , and a plurality of tip propellers 141 associated with each outer wing panel 109 . UAV 101 may further include one or more landing pods 113 to assist in safe landing of UAV 101 at landing site (102, FIG. 1). One or more inner wing panels 107 may be positioned on either side of central panel 108 . In some embodiments, only the inner wing panel 107 may be used without the central panel 108 present. In other embodiments, the inner wing panel 107 may be identical to the central panel 107. One or more outer wing panels 109 may be positioned on either side of one or more inner wing panels 107 and/or central panel 108 . One or more outer wing panels 109 may be arranged at an angle to a plane formed by one or more inner wing panels 107 and/or central panel 108 . In some embodiments, one or more outer wing panels 109 may curve upward with respect to a plane formed by one or more inner wing panels 107 and/or central panel 108 . In one embodiment, UAV 101 has a wingspan of approximately 260 feet and is propelled by multiple motors, e.g., ten electric motors driven by solar arrays covering the surface of each wing, resulting in zero emissions. becomes.

3A, inboard propellers 140 of one or more inner wing panels 107 of UAV 101 and tip propellers 141 of one or more outer wing panels 109 of UAV 101 have propeller hubs 142, propeller blades 144 and propeller blade tips 146, respectively. can contain. In one embodiment, propellers 140 , 141 may each have two blades 144 . In another embodiment, propellers 140 , 141 may each have more than two blades 144 . In one embodiment, propellers 140, 141 may be identical. In _one embodiment, the distance from the center of propeller hub 142 to propeller blade tips 146 is d1. _With respect to the inner wing panel 107, the landing pod 113 adjacent the associated propeller hub 142 has a height d2.

In general, it may be desirable to reduce the height of landing pod 113 to reduce the weight of landing pod 113 and the drag induced by landing pod 113 of UAV 101 . However, reducing the height of landing pod 113 may be limited by distance _d1 . For example, if the height d2 of the landing pod 113 is too low and the distance from the center of the propeller hub 142 to the propeller blade tips 146 is greater _than or _equal to the height d2 of the landing pod ₍ eg, d1 ≤ _d2 ), Rotation of the inboard propeller 140 when the UAV 101 is at or near the ground 150 , such as during takeoff and landing, can cause the blades 144 to strike a surface 150 , such as the ground, and damage the UAV 101 .

In one embodiment, inboard propeller 140 may be leveled such that blades 144 are in an orientation that provides propeller blade clearance to ground 150 when UAV 101 lands. In some embodiments, the orientation that provides clearance for the propeller blades to the ground 150 is where the blades of a two-blade propeller are maintained substantially parallel to the plane formed by the inner wing panel(s). In other embodiments, the blades of a two-blade propeller are planes formed by one or more inner wing panels such that the orientation that provides clearance for the propeller blades to the ground 150 is such that the propeller blades do not contact the ground 150. is maintained at an angle to the plane, for example at an angle to the plane and/or not substantially perpendicular to the plane. In some embodiments, the orientations that provide clearance for the propeller blades to the ground 150 are such that none of the blades of the propeller contact the ground 150 and/or the top propeller blades are substantially oriented with respect to the plane. This is the case when the blades of a three-bladed propeller are maintained so that they are vertical. In one embodiment, inboard propeller 140 and tip propeller 141 may each include a microcontroller 420 . Each microcontroller 420 can communicate with a respective motor for each propeller 140,141. In some embodiments, one microcontroller 420 can control one or more propellers, such as all of the inboard propellers 140 . In one embodiment, each propeller 140 , 141 has an associated microcontroller 420 . In another embodiment, a single microcontroller 420 controls all propellers 140,141. In another embodiment, one microcontroller 420 controls the tip propeller 141 and another microcontroller 420 controls the inboard propeller 140 .

As will be discussed below, tip propeller 141 may be allowed to continue functioning for propulsion and control purposes during landing and takeoff. More specifically, the distance d1 from the center of the propeller hub 142 to the propeller blade tips 146 is _equal to or greater than the height d3 from the center of the propeller hub 142 to the lower end of the landing pod 113 ₍ for example, _d1 ≤ d ₃ ), the height of the landing pod 113 may be set.

FIG. 3B shows a schematic diagram of wing panel 107 and two-blade propeller 140 held against wing panel 107 . Inboard propellers 140 may each include propeller hub 142 , propeller blades 144 and propeller blade tips 146 . In one embodiment, the center of the propeller hub 142 to the propeller blade tips 146 has _a distance d1. _With respect to the inner wing panel 107, the landing pod 113 adjacent the associated propeller hub 142 has a height d2.

In one embodiment, the inboard propeller 140 may be maintained in an orientation that provides propeller blade clearance to the ground 150 . The blades of the two-blade propeller 140 are positioned at an angle 160 to the plane formed by the inner wing panel(s) 107, such as at an angle 160 to the plane, such that the propeller blades 144 do not contact the ground 150. and/or may be maintained substantially non-perpendicular to the plane.

FIG. 3C shows a schematic diagram of the wing panel 107 and the three-blade propeller 141 held against the wing panel. Inboard propellers 141 may each include a propeller hub 142 , propeller blades 145 and propeller blade tips 147 . In _one embodiment, the distance from the center of propeller hub 142 to propeller blade tips 147 is d1. _With respect to the inner wing panel 107, the landing pod 113 adjacent the associated propeller hub 142 has a height d2.

In one embodiment, the inboard propeller 141 may be maintained in an orientation that provides clearance between each propeller blade 145 and the ground 150 . The blades of the three-blade propeller 145 may be maintained at an angle to the plane formed by the inner wing panel(s) 107 so that the propeller blades 145 do not contact the ground 150 . In one embodiment, the uppermost propeller blade (i.e., the propeller blade 145 of the three-blade propeller 145 with the propeller blade tip 147 furthest from the ground 150) is substantially positioned with respect to the plane formed by the inner wing panel 107. may be perpendicular to In other embodiments, the top propeller blades may be held at an angle substantially perpendicular to the plane formed by the inner wing panels 107 . The three-blade propeller 141 is positioned relative to the inner wing panel 107 to provide ground clearance for each propeller blade 145 .

FIG. 4 illustrates an example top-level functional block diagram of an embodiment 400 of a computing device. An exemplary operating environment includes a processor 424 such as a central processing unit (CPU), addressable memory 427, external device interfaces 426, an optional USB port and associated processing, and/or an Ethernet port and associated and an optional user interface 429, such as an array of status lights and one or more toggle switches, and/or a display, and/or a keyboard and/or a pointer-mouse system and/or a touch screen. It is shown as a computing device such as controller 420 . Optionally, the addressable memory is magnetic and floppy disk drives, optical disk drives, magnetic cassettes, tape drives, flash memory cards, digital video disks (DVDs), Bernoulli cartridges, RAM, ROM, smart cards Any type of computer-readable medium that can store data accessible by microcontroller 420, such as. Indeed, any medium for storing or transmitting computer readable instructions and data may be employed, including a connection port to or nodes on a network such as a LAN, WAN or the Internet. These elements can communicate with each other via data bus 428 . In some embodiments, via operating system 425, such as supporting web browser 423 and application 422, processor 424 performs the steps of the process of establishing a communication channel and the steps of processing according to the embodiments described above. It may be configured as follows.

Microcontroller 420 may further include at least one sensor 152, such as an external angular position sensor. In one embodiment, sensor 152 may be a magnetic rotary position sensor, such as a Hall effect rotary position sensor. In another embodiment, sensor 152 is a variable reluctance sensor. In another embodiment, sensor 152 may be an optical sensor. In another embodiment, sensor 152 may be a combination of magnetic and optical sensors. In one embodiment, a combination of magnetic and optical sensors can detect the current position of the blade 144 rather than just detecting the signal of the blade 144 at a particular position, such as a horizontal position.

For magnetic Hall effect sensor embodiments, a magnet may be attached to each blade 144 and the magnetic Hall effect sensor 152 may detect each magnet. This allows sensor 152 to detect the angular position of blade 144 and processor 424 to take steps to continuously control the angular position of blade 144 attached to motor 110 . More specifically, as the UAV 101 approaches the ground 150 for landing and the UAV 101 descends below a threshold altitude, the flight control computer (FCC) sends command signals to each motor 110 associated with the inner wing panel 107. , the blades 144 of the associated inboard propeller or propellers 140 can be held horizontally and locked. A microcontroller 420 controls the speed of the motor 110 thereby leveling, holding and locking the blade 144 . Additionally, the microcontroller 420 associated with the tip propeller 141 can control the speed of the motor 110 for landing and takeoff while the blades 144 associated with the inboard propeller 140 are leveled and locked.

When the rotation of the inboard propeller 140 is stopped, such as when the UAV 101 descends to the landing site 102, the tip propeller 141 continues to rotate and the thrust from the motor 110 to the tip propeller 141 causes the tip propeller 141 to move for landing. UAV 101 can be guided. At or near ground 150 , distance d ₁ is greater than distance d ₃ from propeller hub 142 to ground 150 . This is because the upward facing outer wings 109 always provide a safe distance between the tip propeller 141 and the ground 150 . Thus configured, the non-leveled tip propeller 141 maintains lateral control of the UAV 101 during landing, while the inboard propeller 140 is maintained in a horizontal attitude.

During takeoff of the UAV 101, the inboard propellers 140 are initially oriented in an attitude that provides clearance between the propeller blades and the ground 105, while the leading propellers 141 allow the UAV 101 to take off and climb above the threshold altitude. can provide both sufficient thrust and control capabilities to allow The inboard propeller 140 can then be used for additional propulsion when the UAV 101 climbs above the threshold altitude.

Referring to FIG. 5, a flowchart 500 of steps performed by a microcontroller, such as microcontroller 420, for landing a UAV, such as UAV 101, is shown. At step 502, a sensor may detect the angular position of the UAV's propeller blades. At step 504, the microcontroller processor may perform steps to continuously control the angular position of the blade attached to the motor. In one embodiment, each propeller (tip propeller or inboard propeller) has an associated microcontroller. In another embodiment, one microcontroller controls all propellers. In another embodiment, one microcontroller controls the tip propellers and another microcontroller controls the inboard propellers. In one embodiment, the UAV has a wingspan of about 260 feet and is propelled by multiple motors, for example 10 electric motors, driven by solar arrays covering the surface of each wing, thereby providing zero emissions is realized.

As the UAV approaches the ground for landing and descends below a threshold altitude, the flight control computer (FCC) sends command signals to each motor associated with the UAV's inner wing panel to level the associated propeller blades. can do. At step 506, the motor receives the angular position of the blades and stops propeller rotation in an attitude that provides clearance of the propeller blades to the ground upon landing.

In step 508, when the propeller rotation is stopped as the UAV descends to the landing site, the tip propeller is allowed to continue rotating and the thrust from the motor to the tip propeller causes the tip propeller to propel the UAV for landing. can be induced. In _one embodiment, the distance from the center of the propeller hub to the propeller blade tips is d1. _With respect to the inner wing panel, the landing pod 113 proximate the associated propeller hub has a height d2. The landing pod is tall enough that the distance d3 from the propeller hub center to the propeller blade tip is greater _than or equal to the height d2 of the landing pod ₍ eg _, d1 ≤ _d3 ). At or near the _{ground ,} the distance d1 is greater than the distance d3 from the propeller hub 142 to the ground. This is because the upturned outer wing always provides a safe distance between the tip propeller and the ground. So configured, in step 510, the non-leveled tip propellers retain lateral control of the UAV during landing, while the propellers are held in a horizontal position. In some embodiments, a signal can be sent to the tip propeller to adjust the rotation by increasing the rotation, decreasing the rotation, or maintaining the current rotation. When the inner prop is held, the leading prop can be sped up if desired to maintain the same thrust. In some embodiments, the rotation of the tip propeller can be increased, remained the same, or decreased as desired for control purposes.

Referring to FIG. 6, a flowchart 600 of steps performed by a microcontroller, such as microcontroller 420, for takeoff of a UAV, such as UAV 101, is shown. The method 600 may include detecting an angular position of an inboard propeller blade with a sensor in communication with a microcontroller (step 602). The method 600 may then include the processor of the microcontroller performing the step of continuously communicating the angular position of the inboard blade to the motor (step 604). The method 600 may then include the step of the motor receiving the angular position of the inboard blades at the microcontroller, and the microcontroller's processor confirming that the inboard propeller blades are at the proper attitude. Yes (step 606). Risk of the rotating inboard propeller blades hitting the ground during takeoff if the inboard propeller blades are not properly positioned during rotation, i.e. the inboard propeller blades are not held in place There is If the inboard propeller blades are not properly oriented with respect to the inner wing panel, the microcontroller processor will send a signal to halt takeoff or send a signal to hold the propeller blades in a proper orientation. corrective action can be taken. The method 600 may then include allowing the leading propellers to retain lateral control of the UAV during takeoff while the inboard propellers are held in place (step 610). The tip propeller can provide the necessary thrust for UAV takeoff while the inboard propeller is held in place to prevent it from hitting the ground during takeoff. The method 600 may then include continuing the tip propeller to rotate while the microcontroller initiates the rotation of the inboard propeller as the UAV ascends from the takeoff point (step 608). In some embodiments, the thrust generated by the tip propeller can be reduced as the inboard propeller begins to rotate in order to balance the thrust generated by the sum of all of the tip and inboard propellers. can.

Various combinations and/or subcombinations of the specific features and aspects of the above embodiments may be made and are intended to be within the scope of the invention. As such, it should be understood that various features and aspects of the disclosed embodiments can be combined with each other or substituted for one another to form various modes of the disclosed invention. Further, it is intended that the scope of the present invention, although disclosed herein by way of example, should not be limited by the specific disclosed embodiments described above.

Claims (20)

an unmanned aerial vehicle (UAV);
one or more inner wing panels of the UAV;
One or more outer wing panels of a UAV, said one or more outer wing panels being positioned on either side of said one or more inner wing panels, said one or more outer wing panels one or more outer wing panels disposed at an upward angle to a plane formed by the plurality of inner wing panels;
at least one inboard propeller attached to at least one engine located on the one or more inner wing panels;
at least one tip propeller attached to at least one engine located on the one or more outer wing panels;
at least one microcontroller in communication with at least one engine located on the one or more inner wing panels,
determining the angular position of the at least one inboard propeller;
at least one configured to transmit a signal to stop rotation of the at least one inboard propeller such that the at least one inboard propeller is held in an orientation that provides clearance of the propeller blades to the ground during landing; and a microcontroller. The system of claim 1, wherein
A system, wherein said UAV is a high endurance aircraft. The system of claim 1, wherein
The system, further comprising a solar array covering at least a portion of the one or more inner wing panels and the one or more outer wing panels. The system of claim 1, wherein
A system, further comprising one or more landing pods of a UAV, wherein said one or more landing pods are attached to said one or more inner wing panels of said UAV to assist in landing said UAV. . 5. The system of claim 4, wherein
the distance from the center of the propeller hub to the tip of the at least one inboard propeller is greater than the height of the one or more landing pods, and during rotation of the at least one inboard propeller when the UAV is on the ground; A system, wherein said at least one inboard propeller can hit the ground. 6. The system of claim 5, wherein
A system, wherein at least one outboard propeller is identical to said at least one inboard propeller, said at least one outboard propeller being free to rotate when the UAV is on the ground. The system of claim 1, wherein
A system, further comprising a position sensor in communication with said microcontroller, said position sensor detecting a position of said at least one inboard propeller. A system according to claim 7, wherein
A system, wherein said position sensor is a Hall effect rotary position sensor. The system of claim 1, wherein
The at least one microcontroller further:
determining the altitude of the UAV;
A system configured to transmit a signal to stop rotation of the at least one inboard propeller when the determined altitude is below a threshold altitude. 10. The system of claim 9, wherein
The at least one microcontroller further:
configured to transmit a signal to adjust rotation of the at least one outboard propeller while the at least one inboard propeller is held in an orientation that provides propeller blade clearance to the ground; characterized system. The system of claim 1, wherein
The at least one microcontroller further:
determining the altitude of the UAV;
A system configured to transmit a signal to initiate rotation of the at least one inboard propeller when the determined altitude is above a threshold altitude. determining, by at least one microcontroller, an altitude of an unmanned aerial vehicle (UAV);
determining, by the at least one microcontroller in communication with at least one engine of a UAV, the angular position of at least one inboard propeller connected to the at least one engine, the at least one inboard propeller. is positioned on the one or more inner wing panels;
by the at least one microcontroller such that when the identified altitude is below a threshold altitude, the at least one inboard propeller is held in an attitude that provides propeller blade clearance to the ground during landing; sending a signal to stop rotation of the inboard propeller;
A method, wherein the at least one inboard propeller may hit the ground during rotation of the at least one inboard propeller when the UAV is on the ground. 13. The method of claim 12, wherein
of the at least one outboard propeller connected to the at least one engine by the at least one microcontroller while the at least one inboard propeller is held in an orientation that provides clearance of the propeller blades to the ground during landing; further comprising transmitting a signal to adjust the rotation;
A method, wherein said at least one outboard propeller is located on one or more outer wing panels. 14. The method of claim 13, wherein
A method, wherein said at least one outboard propeller is identical to said at least one inboard propeller, said at least one outboard propeller being free to rotate when the UAV is on the ground. an unmanned aerial vehicle (UAV);
at least one inboard propeller attached to at least one engine of a UAV, at least a portion of said at least one inboard propeller during rotation of said at least one inboard propeller when said UAV is located on the ground; at least one inboard propeller that can contact the ground;
At least one tip propeller attached to at least one engine of a UAV that rotates freely without contacting the ground surface during rotation of the at least one tip propeller when the UAV is located on the ground surface. at least one tip propeller capable of
at least one microcontroller in communication with the at least one engine, comprising:
determining the angular position of the at least one inboard propeller;
at least one microcontroller configured to send a signal to the at least one inboard propeller such that the at least one inboard propeller is held in an orientation that provides propeller blade clearance to the ground surface. A system characterized by: 16. The system of claim 15, wherein
The at least one microcontroller further:
Sending a signal to the at least one leading propeller to adjust thrust for guiding the UAV for landing while the at least one inboard propeller is held in an attitude that provides propeller blade clearance to the ground. is configured to
A system, wherein said at least one tip propeller maintains lateral control of the UAV during landing. 16. The system of claim 15, wherein
The at least one microcontroller further:
and while the at least one inboard propeller is in an attitude that provides propeller blade clearance to the ground, to send a signal to the at least one leading propeller to adjust thrust for guiding the UAV for takeoff. wherein said at least one tip propeller maintains lateral control of the UAV during takeoff;
The at least one microcontroller is further configured to send a signal to the at least one inboard propeller after takeoff so that the at least one inboard propeller begins to rotate. system. 16. The system of claim 15, wherein
further comprising one or more landing pods to assist in safely landing the UAV on the ground, wherein the distance from the center of the propeller hub to the tip of the at least one inboard propeller is greater than the height of the one or more landing pods. and the distance from the center of the propeller hub to the tip of the at least one tip propeller is greater than or equal to the height from the center of the propeller hub of the at least one tip propeller to the bottom edge of the one or more landing pods. A system characterized by: 19. The method of claim 18, wherein
one or more inner wing panels of a UAV, wherein the at least one inboard propeller is mounted;
One or more outer wing panels of a UAV, wherein said at least one tip propeller is attached to said one or more outer wing panels, and said one or more outer wing panels are attached to said one or more inner wing panels. and wherein said one or more outer wing panels are arranged at an upward angle to a plane formed by said one or more inner wing panels A method, further comprising: 16. The system of claim 15, wherein
A system, further comprising a position sensor in communication with said microcontroller, said position sensor detecting a position of said at least one inboard propeller.

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